Portable humidifier



May 4, 1965 1-. c. GLAZE PORTABLE HUMIDIFIER Filed March 10 1961 3 Sheets-Sheet 1 Q. I all INVENTOR.

THOMA 8 y 4, 1965 T. c. GLA ZE 3,181,844 PORTABLE HUMIDIFIER Filed March 10. 1961 3 Sheets-Sheet 2 INVENTOR. 72 0/1446 C. 64 A236 Filed March 10 1961 Y 4, 1965 v v T. c. GLAZE 3,181,844

I PORTABLE HUMIDIFIER 3 Sheets-Sheet 3 *9 w I I 11 INVENTOR. THdMlJ 6'. 64 425 BY MW United States Patent 3,181,844 PORTABLE HUMIDIFIER Thomas C. Glaze, Lancaster, Calif., assignor to the United States of America as represented by the Secretary of the Air Force Filed Mar. 10, 1961, Ser. No. 94,951 2 Claims, ((11. 261-130) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the United States Government for governmental purposes without payment to me of any royalty thereon.

This invention relates to portable humidifiers and more particularly to portable humidifiers capable of supplying air to a test chamber at temperatures of 50 F. to 180 F. at a relative humidity of up to 95 percent. It is especially useful in testing components which may be subjected to such conditions in use.

It is comparatively easy to design and build a device for humidifying air and either cooling or heating it for human comfort in the range of temperatures encountered in homes, cars and the like, and there are many such devices. It is much more difiicult to design and build a humidifier which operates in the range of 50 to 180 F. with a relative humidity ranging up to 95 percent.

It is very desirable to have such a humidifier which can be moved from place to place and it is an object of this invention to provide such a device.

It is a further object to provide such a device which can be manufactured cheaply from readily available materials and parts.

It is a further object to provide such a device with simple power supply requirements and which requires a minimum of man hours to change from one test system to another.

The above and still other objects, advantages and features of my invention will become apparent upon consideration of the following description of one embodiment thereof, especially when taken in conjunction with the acompanying drawings, in which:

FIGURE 1 is a side view of the invention;

FIGURE 2 is a schematic top view of FIGURE 1;

FIGURE 3 is an end view of FIGURE 1;

FIGURE 4 is an exploded view of the humidity pad assembly; and

FIGURE 5 is a pictorial view of the heating element assembly.

In the drawings represents a casing which may be of rectangular cross-section. The numerals 12 and 14 represent transition ducts changing from rectangular to round to accommodate round, flexible ducts 16 (only 1 shown), one of which leads to a source of air and the other to a test chamber. A conventional heating element assembly 18, shown in detail in FIGURE 5, is located just after the intake duct 14 (FIGURE 2). Behind the said heating element assembly 18, in the direction of flow of air through the device, is a humidity pad assembly 2t), shown in detail in FIGURE 4. The heating element assembly 18 comprises two conventional coils of resistance wire, 64 and 66, mounted within a frame 68 and criss-crossing the opening. The coils of wire 64 and 66 are supported by porcelain insulators 70. The heating wire is heated by the passage of electric current through it and is controlled by a thermostatic switch 22 located in intake duct 14. The humidity pad assembly comprises a pad of water absorbing material 76, such as aspen shavings or the like, packed between wire screen mesh elements 78 held in a suitable frame 72 by cross bars 80. Placed above the said humidity pad 20 is a distributing tube 38 entering said frame 72 through a hole 74 therein. The

3,181,844 Patented May 4, 1965 Ice tube 38 has holes drilled in the under side thereof to drip water on the said pad in a controlled amount. In the said distributing tube 38 is an orifice or restriction, not shown, so designed that under no conditions will the amount of water passed through it hood the pad unit 20. A valve 44 controls the quantity of water admitted to the said distributing tube 38 which water is heated to a suitable temperature in a mixing chamber 40 by the admission of steam through a valve 34 and cold Water through a valve 36. A thermometer 42 registers the temperature of the water in the mixing chamber 40 and a bleeder valve 46 permits a flow of water through the said mixing chamber so as to bring it to a suitable temperature. In another embodiment (not shown) the mixing chamber 46) might comprise a cold water inlet with a Calrod heating unit to bring the water to the proper temperature.

In FIGURE 2, two motors are shown, one large, 26, and one small, 28, which are connected to blower fans housed in compartments 30 and 32, respectively. Check valves placed at prevent recirculation of the air through the dormant blower when only one is used. The direction of air flow through the device is shown by the arrows in FIGURE 2 and the amount of air is controlled by inlet and outlet dampers 48. The position of the dampers is controlled by handles 50 which are journalled in bushings 62.

Referring to FIGURES 1 and 3, the casing 11} rests on a frame 54 which is provided with swivel wheels 56 and stationary wheels 58, making the humidifier easily moved from place to place. A motor support 52 holds the large motor 26 in position.

In the discharge end of the device is shown in FIGURE 3, wet and dry bulb thermometers 25 and 24, which, by reference to a chart, shows the relative humidity of the discharged air.

In use a flexible duct 16, such as shown at the inlet in FIGURE 1, is attached to the output of the humidifier and connected to the test chamber. The duct 16 at inlet is connected to a supply of air or, if desired, may be omitted under certain conditions. Water and steam are admitted to the mixing chamber through valves 34 and 36 and bleeder valve 46 is opened to allow a circulation and mixing of the steam and water. The motors are then turned on and the temperature and humidity of the outgoing air is noted on the wet and dry bulb thermometers 25 and 24. The steam and water valves 34 and 36 are then manipulated, and the thermo switch adjusted until the desired temperature and humidity is attained.

It is to be noted that to achieve the high temperature and humidity conditions of which this humidifier is capable, it is necessary to have not only means to heat the air but means to heat the humidity pad. This is accomplished by mixing steam with the water supplied to the pad and is necessary because evaporation in the humidity pad tends to cool the air passing through it. Without heating of the water in the humidity pad the high temperatures required of this device would be diflicult to obtain.

This device, being readily portable, and capable of being taken to a machine or installation having parts assembled therein which require testing, is very useful. Unassernbled components can be readily tested by placing them in a humidity chamber connected to a permanent installation, but to test the same components after assembly and under actual conditions of use requires a humidifier which can be moved to the machine or installation.

What I claim as new is:

1. A portable humidifier capable of furnishing air at a temperature from 50 F. to 180 F. and up to percent relative humidity comprising, a casing mounted on wheels and having an inlet and an outlet, a pair of motors in said casing, fans connected to said motors adjacent said outlet and in communication with said inlet to draw air from said inlet to said outlet through said casing in varying amounts, an electric heating element fixed in said casing adjacent said inlet and interposed in said air to heat said air, thermostatic means responsive to the temperature of the air in said inlet for controlling said heater for outlet temperatures of up to 180 F., a humidity pad interposed in said air downstream of said heating element and upstream of said fans to humidity said heated air, said pad comprising Water absorbent material and a frame of wire mesh for holding said material, means to supply Water to saturate said pad, heating means for controlling the temperature of said Water to said pad, the amount and temperature of said water together with said heated air allowing for up to 95 percent relative humidity and settable damper means at said inlet and said outlet for controlling the air flow through said casing to facilitate the control of temperature and relative humidity.

2. A device as described in claim 1 wherein said means for controlling the temperature of said water to said pad comprises a mixing chamber, a steam source and a cold Water source connected to said chamber, and valves con- A 4 nected to each of said sources for regulating the flow of steam and Water to said chamber to generate heated water.

References Cited by the Examiner UNITED STATES PATENTS 1,101,902 6/14 Braemer 261 XR 1,821,297 9/31 Driscoll 165-60 1,848,576 3/32 Sandel 261-98 XR 1,872,195 8/32 Thompson 257 -138 XR 1,984,658 12/34 Rourke 26126 XR 2,110,268 3/38 Harris -222 2,123,742 7/38 Often 261 XR 2,236,359 3/41 Armstrong 26126 XR 2,239,595 4/41 Cummings 26127 XR 2,277,5 52 3/42 Kneedler.

2,356,757 8/44 Fleisher 55233 XR 2,391,558 12/45 Essick 55233 XR 2,856,937 10/58 Harris 26129 XR 20 HARRY B. THORNTON, Primary Examiner.

HERBERT L. MARTIN, Examiner. 

1. A PORTABLE HUMIDIFIER CAPABLE OF FURNISHING AIR AT A TEMPERATURE FROM 50*F. TO 180*F, AND UP TO 95 PERCENT RELATIVE HUMIDITY COMPRISING, A CASING MOUNTED ON WHEELS AND HAVING AN INLET AND AN OUTLET, A PAIR OF MOTORS IN SAID CASING, FANS CONNECTED TO SAID MOTORS ADJACENT SAID OUTLET AND IN COMMUNICATION WITH SAID INLET TO DRAW AIR FROM SAID INLET TO SAID OUTLET THROUGH SAID CASING IN VARING AMOUNTS, AN ELECTRIC HEATING ELEMENT FIXED IN SAID CASING ADJACENT SAID INLET AND INTERPOSED IN SAID AIR TO HEAT SAID AIR, THERMOSTATIC MEANS RESPONSIVE TO THE TEMPERATURE OF THE AIR IN SAID INLET FOR CONTROLLING SAID HEATER FOR OUTLET TEMPERATURES OF UP TO 180*F., A HUMIDITY PAD INTERPOSED IN SAID AIR DOWNSTREAM OF SAID HEATING ELEMENT AND UPSTREAM OF SAID FANS TO HUMIDITY SAID HEATED AIR, SAID PAD COMPRISING WATER ABSORBENT MATERIAL AND A FRAME OF WIRE MESH FOR HOLDING SAID MATERIAL, MEANS TO SUPPLY WATER TO SATURATE SAID PAD, HEATING MEANS FOR CONTROLLING THE TEMPERATURE OF SAID WATER TO SAID PAD, THE AMOUNT AND AND TEMPERATURE OF SAID WATER TOGETHER WITH SAID HEATED AIR ALLOWING FOR UP TO 95 PERCENT RELATIVE HUMIDITY AND SETTABLE DAMPER MEANS AT SAID INLET AND SAID OUTLET FOR CONTROLLING THE AIR FLOW THROUGH SAID CASING TO FACILITATE TO CONTROL OF TEMPERATURE AND RELATIVE HUMIDITY. 